Article thumbnail
Location of Repository

Specific inhibition of the synthesis of putrescine and spermidine by 1,3-diaminopropane in rat liver in vivo

By H. Pösö, A. Kallio, G. Scalabrino and J. Jänne

Abstract

Chronic administration of 1,3-diaminopropane, a compound inhibiting mammalian ornithine decarboxylase (EC 4.1.1.17) in vivo, effectively prevented the large increases in the concentration of putrescine that normally occur during rat liver regeneration. Furthermore, repeated injections of diaminopropane depressed by more than 85% ornithine decarboxylase activity in rat kidney. Administration of diaminopropane 60 min before partial hepatectomy only marginally inhibited ornithine decarboxylase activity at 4 h after the operation. However, when the compound was given at the time of the operation (4 h before death), or any time thereafter, it virtually abolished the enhancement in ornithine decarboxylase activity in regenerating rat liver remnant. An injection of diaminopropane given 30 to 60 min after operation, but not earlier or later, depressed S-adenosyl-L-methionine decarboxylase activity (EC 4.1.1.50) 4 h after partial hepatectomy. Diaminopropane likewise inhibited ornithine decarboxylase activity during later periods of liver regeneration. In contrast to early regeneration, a total inhibition of the enzyme activity was only achieved when the injection was given not earlier than 2 to 3 h before the death of the animals. Diaminopropane also exerted an acute inhibitory effect on adenosylmethionine decarboxylase activity in 28-h regenerating liver whereas it invariably enhanced the activity of tyrosine aminotransferase (EC 2.6.1.5), used as a standard enzyme of short half-life. Treatment of the rats with diaminopropane entirely abolished the stimulation of spermidien synthesis in vivo from [14C]methionine 4 h after partial hepatectomy or after administration of porcine growth hormone. Both partial hepatectomy and the treatment with growth hormone produced a clear stimulation of hepatic RNA synthesis, the extent of which was not altered by injections of diaminopropane in doses sufficient to prevent any enhancement of ornithine decarboxylase activity and spermidine synthesis

Topics: Animals, Ornithine Decarboxylase, Propylamines, Tyrosine Transaminase, Liver Regeneration, Rats, Putrescine, Spermidine, Liver, Adenosylmethionine Decarboxylase, Time Factors, Male, Growth Hormone, Settore MED/04 - Patologia Generale
Publisher: 'Elsevier BV'
Year: 1977
DOI identifier: 10.1016/0304-4165(77)90162-3
OAI identifier: oai:air.unimi.it:2434/181457
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://hdl.handle.net/2434/181... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.